How to Use DHT20: Examples, Pinouts, and Specs

The DHT20, manufactured by AZ-Delivery, is a digital temperature and humidity sensor that provides accurate and reliable measurements. It uses a capacitive humidity sensor and a thermistor to measure the surrounding air and outputs a digital signal on the data pin. This sensor is widely used in various applications, including weather stations, HVAC systems, and environmental monitoring.

1. Power Supply: Connect the VCC pin to a 3.3V or 5V power supply and the GND pin to the ground.
2. I2C Communication: Connect the SDA pin to the SDA pin on your microcontroller and the SCL pin to the SCL pin on your microcontroller.
3. Pull-up Resistors: Use 4.7kΩ pull-up resistors on the SDA and SCL lines if they are not already present on your microcontroller board.

• Stable Power Supply: Ensure a stable power supply to avoid fluctuations that can affect sensor readings.
• Proper Placement: Place the sensor in a location where it can accurately measure the ambient temperature and humidity without interference.
• Avoid Condensation: Avoid placing the sensor in environments where condensation can occur, as this can damage the sensor.

#include <Wire.h>
#include "DHT20.h"

DHT20 dht20;

void setup() {
  Serial.begin(9600);
  Wire.begin();
  dht20.begin();
}

void loop() {
  float temperature = dht20.readTemperature();
  float humidity = dht20.readHumidity();

  Serial.print("Temperature: ");
  Serial.print(temperature);
  Serial.println(" °C");

  Serial.print("Humidity: ");
  Serial.print(humidity);
  Serial.println(" %");

  delay(2000); // Wait for 2 seconds before the next reading
}

1. No Data Output:

   • Solution: Check the wiring connections and ensure that the SDA and SCL lines are correctly connected. Verify that the pull-up resistors are in place.

2. Inaccurate Readings:

   • Solution: Ensure that the sensor is placed in an environment free from rapid temperature changes or condensation. Verify that the power supply is stable.

3. Sensor Not Detected:

   • Solution: Ensure that the I2C address of the sensor matches the address used in the code. Check for any loose connections or damaged wires.

Q1: Can the DHT20 be used with a 3.3V microcontroller?

• A1: Yes, the DHT20 can operate with a power supply ranging from 3.3V to 5.5V.

Q2: What is the maximum distance for the I2C communication?

• A2: The maximum distance for reliable I2C communication is typically around 1 meter. For longer distances, consider using I2C bus extenders.

Q3: How often should I take readings from the DHT20?

• A3: It is recommended to take readings at intervals of at least 2 seconds to allow the sensor to stabilize.

By following this documentation, users can effectively integrate the DHT20 sensor into their projects, ensuring accurate and reliable temperature and humidity measurements.